history faculty, university of oxford, old boys’ high...

on May 31, 2018http://rsnr.royalsocietypublishing.org/Downloaded from

Notes Rec. R. Soc. (2010) 64, 229–250

doi:10.1098/rsnr.2009.0079

*b

Published online 10 February 2010

EXPLORING AND COMMUNICATING KNOWLEDGE OF TREES

IN THE EARLY ROYAL SOCIETY

by

BERYL HARTLEY*

History Faculty, University of Oxford, Old Boys’ High School,

George Street, Oxford OX1 2RL, UK

For nearly 150 years after its foundation, Fellows of the Royal Society collected information

on trees, investigated their anatomy and physiology, promoted planting and improved

planting practices, and introduced, naturalized and classified foreign species. Their

discoveries and advice were widely disseminated and used. Historians have generally

neglected this interest, although the Society’s first publication was an influential work on

trees. They have also overlooked the significance of Stephen Hales’s remark in Vegetable

Staticks—that he hoped his enquiries into the nature of plants would improve skills in

agriculture and gardening—and his linking of sap movement to tree pruning. Fellows’

experiments and field trials not only advanced knowledge of the structure, nutrition and

growth of trees but also provided empirical evidence supporting instructions for

cultivating them.

eryl

Keywords: early Royal Society; John Evelyn; Stephen Hales; naturalhistory; experiments and field trials; communicating knowledge of trees

TREE PLANTING: PATRIOTISM AND PROFIT

The first publication to receive the Royal Society’s imprimatur was John Evelyn’s Sylva, or a

Discourse of Forest-Trees and the Propagation of Timber, published in 1664 in response to

an appeal from the Navy for the Society to encourage the preservation and planting of oaks,

urgently needed for shipbuilding after great losses and damage to timber trees during the

Civil War and interregnum.1 The appeal, in the form of ‘Quaeries’ (see appendix 1), was

presented to the Society on 17 September 1662 by Sir Robert Moray (FRS 1660).2

Composed by Commissioner of the Navy, Peter Pett, it concerned replanting the royal

forests, chases and parks—‘almost wholly cut down and decayed’—with oaks and other

ship-timber and assumed that Charles II could be persuaded that this would benefit both

the royal purse and the Navy. Pett also proposed that the King should have first refusal of

all suitable timber on private land, at a price agreed between Commissioners and

landowners; that using oak for house-building in and around London should be forbidden

[email protected]

229 This journal is q 2010 The Royal Society

mailto:[email protected]

http://rsnr.royalsocietypublishing.org/

B. Hartley230


(imported fir being substituted); and that all landowners in England and Wales should plant

one acre in every hundred with oaks or elms.3

Pett would have discussed this document with Samuel Pepys, then Clerk of the Acts, whose

Diary mentions their meetings, including two in June and August 1662 with Sir John Winter,

colliery manager in the Forest of Dean, when they read his previous contract with the King and

‘talked of . . . the timber there’ (on another occasion Pepys and Winter discussed a new contract

and studied a map of the Forest).4 Gaps in Royal Society records concerning its deliberations

on the forests are partly filled by Pett’s letter to Evelyn of 4th November 1662, on ‘ye great

business of ye Forest of Deane which is now on foot’. Pett wrote that the Society, having

answered the ‘Quaeries’ he gave to Lord Brouncker (FRS 1660) and Moray, had ‘much

enlarged upon that subject’; he begged Evelyn to bring the relevant passages to the meeting

next day at Gresham College, where he might see them.5

A significant result of the Navy’s request, which accorded with the early Society’s

Baconian aspiration for its work to be useful, was that it provoked a long passage in

Sylva on improving the Forest of Dean and the other royal forests (including enclosing

land for planting) in which Evelyn—presumably with the Society’s support—urged the

King to ‘assert his power’ over those in charge who were neglecting their duties. He

urged landowners to plant and preserve forest trees, especially on barren land, citing

exemplars already finding this financially rewarding; he suggested removing some iron

mills and advocated an Act to preserve standard trees, unless in decay. Evelyn

recommended to the King, Parliament and Commissioners that county deputies—

accountable to ‘the Lord Treasurer and to the principal Officers of His Majesties Navy’—

be appointed to monitor woods, ensuring swift prosecution of improvements and reform

of defects; and that ‘such proportions of Timber etc. were planted and set out upon every

hundred or more of Acres as the Honorable Commissioners have suggested . . . ’. Evelyn

concluded, provocatively:

the care of so publick and honourable an Enterprize as is this of Planting and Improving

of Wood, is a right noble and royal undertaking . . . more worthy of a Prince who truly

consults his glory in the highest Interest of his Subjects than that of gaining Battels, or

subduing a Province.6

Sylva received royal approval, and more than a thousand copies were sold, resulting, Evelyn

declared, in more than two million timber trees being planted.7 Its success may be attributed

to the fact that, while encouraging landowners to enhance their estates with ornamental and

fruit trees, Evelyn also presented powerful economic arguments in favour of planting timber

trees—a further incentive for them to obey their patriotic duty.

Until fairly recently Evelyn was universally accepted as Sylva’s author, which is hardly

surprising because in Godfrey Kneller’s 1689 portrait he is depicted proudly holding a

copy (figure 1), his name appeared alone on the title page, and he always referred to ‘my

Sylva’; moreover, the Society’s proceedings and imprimatur attribute the treatise to him.8

Scholars, however, have now shown that although Evelyn’s role was central, Sylva

originated as a collective endeavour undertaken within the early Society’s Baconian

ethos.9 Evelyn, John Goddard (FRS 1660), Christopher Merret (FRS 1660) and John

Winthrop (FRS 1662), who had previously shown an interest in trees, were asked to

respond to the Navy’s request,10 but Evelyn—already an acclaimed author and

experienced planter and gardener11—combined their papers. This ad hoc committee was

one of several concerned with agricultural improvements—‘a model for the collective


Figure 1. Portrait by Sir Godfrey Kneller of John Evelyn holding Sylva; oil on canvas (1689). Painted for Samuel Pepys(Evelyn, Diary, 8 July 1689). (Royal Society Library; copyright q The Royal Society; online version in colour.)

Exploring and communicating knowledge of trees 231


inquiry the Society wished to promote’.12 As a Baconian, Evelyn would no doubt have

collaborated willingly13 and he acknowledged the assistance of ‘divers Worthy Persons’;14

their contributions add weight to his discourse.

TOWARDS A NATURAL HISTORY OF TREES

Evelyn’s title was evidently intended to link Sylva to Bacon’s Sylva Sylvarum, the eighth

edition of which also appeared in 1664, subtitled ‘a Natural History’. Fellows probably


B. Hartley232


envisaged Sylva as contributing to a cumulative natural history of trees.15 It contained a fund

of empirical evidence about trees and advice on their cultivation and use—based on personal

observation and experiment where possible, as Bacon had advocated16—mingled with

anecdotes, myth, folklore and remarks on extraordinary trees, on forests, woods and

planting barren land.

Collecting material for such a history was in tune with the Society’s ‘Baconian-inspired

programme of information-gathering’, considered crucial to effecting improvements.17

Strangely, considering the need to encourage planting, the first questionnaire, circulated

by the Georgical Committee and printed in Philosophical Transactions in 1665—

‘Enquiries concerning Agriculture’—omitted timber trees.18 In the following year,

however, when Robert Boyle (FRS 1660) published ‘General Heads for a Natural History

of a Countrey, Great or Small’,19 his list of ‘external productions of the Earth’ to be

recorded included timber trees of ‘great bulk’ and ‘what coppices, groves, woods and

forests the Country has or wants . . . what soyles they most like or dislike; and with what

Culture they thrive best.’ Boyle probably knew Arnold Boate’s Natural History of Ireland,

which recorded timber in its survey of natural resources.20 Robert Plot (FRS 1677)

successfully used questionnaires to obtain information on trees and other matters and

Natural History of Oxfordshire (1677) and Natural History of Staffordshire (1686)

contained details of woods, a practice emulated in subsequent county surveys.21 For later

editions of Sylva, Evelyn drew on Plot’s Histories and works by John Ray (FRS 1667) for

further information about extraordinary trees,22 which were not only wonders of nature

but also often attained an immense size, indicating that mature trees, if not felled

prematurely—a practice that Evelyn deplored23—could supply much valuable timber.24

IMPROVING PLANTING PRACTICES

Sylva’s publication was also connected to the Society’s plan for a complete system of

agriculture linked to a collaborative Baconian History of Trades intended to reform

practical knowledge.25 Evelyn, Boyle, Henry Oldenburg (FRS 1663) and John Beale (FRS

1663) were among those connected to Samuel Hartlib’s circle of puritan reformers with

aspirations to improve agriculture, including the cultivation of fruit and timber trees.26

They took their Baconian ideals and projects with them to the Royal Society, of which

they were all founding or early Fellows,27 and attempted ‘to inculcate a more scientific

attitude to husbandry’, seeking improvements that could be verified by experiment.28 Such

attitudes and aims are apparent throughout Sylva—and Pomona, the discourse on fruit

trees and cider production published with it, mainly the work of Beale, author of

Herefordshire Orchards, a Pattern for All England (1657). He was indefatigable in

promoting and publicizing agricultural advances, especially through Philosophical

Transactions; his many letters to Evelyn and Oldenburg indicate his contributions to

Evelyn’s works.29

Evelyn derived Sylva’s practical advice—also expressed as Baconian aphorisms30—from

the ancients, from earlier English works, and from personal experience. He concentrated on

raising seeds, establishing tree nurseries, transplanting young oaks, coppicing, and valuing

and felling timber; he stressed the importance of skilful pruning but deferred to the

experience of ‘our Country-man, honest Lawson’, quoting his instructions at length.31

Evelyn raised many trees planted at Sayes Court in his own nurseries32 and he evaluated




his field trials, encouraging readers to do likewise: ‘Try all sort of seeds,’ he urged, ‘and by

their thriving you shall best discern what are the most proper kinds for Grounds . . . .’33 In

1706 Sylva included a ‘Table of Soils and Situations’ for trees, based on trials, to which

later writers referred.34 Promoting a comparative method reflected the experimental ethos

of Sylva—an important legacy of the work.

Evelyn’s early advice would have assisted inexperienced planters. John Houghton (FRS

1680), who edited A Collection for the Improvement of Husbandry and Trade (1692–

1703), summarized some of it, as well as Evelyn’s remarks on tree species.35 It is clear,

however, that maintaining Sylva’s utility was important: ‘Many more useful Observations

are to be collected . . . from the diligent experience of Planters’, Evelyn stated, and an

advertisement in Philosophical Transactions requested readers to send additions or

improvements to Oldenburg.36 Contributions from many sources appeared in later

editions; Evelyn also drew on the detailed instructions in an acclaimed work by another

practical man, Moses Cook, head gardener to the Earl of Essex.37

Later innovations

Evelyn said little on managing timber plantations—essential to the Society’s original

purpose—but the subject was addressed by later writers, including Richard Bradley (FRS

1712) and Philip Miller (FRS 1730). Bradley, first Professor of Botany at Cambridge,38

was a prolific writer on husbandry: A Philosophical Account of the Works of Nature

(1721), containing a chapter on propagating timber trees and improving barren lands by

planting, attracted more than 500 subscribers, including Isaac Newton, Hans Sloane and

Christopher Wren, as well as French naturalists Etienne-Francois Geoffroy and Bernard de

Jussieu. Important new advice on managing forest trees appeared in New Improvements of

Planting and Gardening (1717), The Gentleman’s and Gardener’s Kalendar (1718) and

his other works. Bradley also performed a useful service by appending Beale’s

Herefordshire Orchards to the former from 1724 and by publishing a revised edition of

Houghton’s Collections, containing Evelyn’s ‘Table of Soil and Situations’, Plot’s

Enquiries and much additional information on trees.39

Philip Miller was Superintendent of the Chelsea Physic Garden (1722–70) and author of

the universally esteemed Gardener’s Dictionary, which ran to eight editions (1731–68) and

six abridgements (1735–71);40 although not confined to trees, in terms of botanical

knowledge of tree species and planting advice it represented a great advance on Sylva.

Miller’s detailed instructions for raising oaks—still considered the most important timber

tree—decreed that extensive plantations be sown ‘where they are to remain’.41 Miller

always emphasized his considerable planting experience,42 claiming to have planted large

numbers of Scotch firs; his instructions on raising evergreens were especially valuable,

little then being known about them.43 He was reported to have advised many

landowners44 including the fourth Duke of Bedford (FRS 1742), who probably consulted

him regarding the famous ‘Evergreens’ plantation at Woburn.45

Bradley and Miller cited Evelyn but challenged his advice on the basis of their own

experience. Nevertheless, Sylva’s influence persisted into the nineteenth century thanks to

Dr Alexander Hunter (FRS 1775), founder of the York Agricultural Society and editor

of the well-known Georgical Essays (1769), who in 1776 published the first of five

editions of Silva.46 It incorporated Linnaeus’s taxonomic system and binomial

nomenclature, brought Evelyn’s advice up to date, and drew on the work of Bradley,


B. Hartley234


Miller and others. The Royal Society was not involved in this venture, but the 650

subscribers, mainly landowners and gardeners, also included the naturalist-Fellows Joseph

Banks, Peter Collinson, Thomas Pennant, John Lightfoot, Daniel Solander and Richard

Kaye. Hunter attributed its success to the recommendation of his ‘patron’, almost

certainly Joseph Banks (FRS 1766)—a friend, also interested in agricultural improvement

and planting.47 Banks no doubt actively encouraged Hunter’s project, perhaps by paying

for the botanical plates (figure 2) and tables, which he checked for accuracy;48 certainly,

as a botanist, he would have welcomed a Linnaean edition of Silva incorporating the

latest planting practices. The third Duke of Portland (FRS 1766) also assisted Hunter by

paying for Silva’s portraits of his famous oaks by the well-known artist S. H. Grimm, and

allowed his head gardener, William Speechley, to contribute valuable instructions on

raising oak plantations.49

The Society of Arts’ planting awards

Although individual Fellows remained dedicated to effecting agricultural reform, the Royal

Society withdrew from technological improvement; however, the Society of Arts, established

in 1754 to promote such matters,50 awarded premiums for timber production from 1757. Of

the four founding members who were Fellows of the Royal Society—Henry Baker, Stephen

Hales, James Short and Gustavus Brander—Baker, a botanist (FRS 1740), did most to foster

planting. He presented a pamphlet by Edward Wade advocating planting timber trees on

common land and waste ground (which cited Evelyn on potential profits),51 and his

proposal to award medals rather than monetary premiums to landowners52 encouraged

many important participants. Peter Collinson (FRS 1728), John Ellis (FRS 1754) and

Miller—arguably the most eminent botanist-gardeners with the greatest knowledge of tree

species at that time—were invited to discuss the first advertisement offering premiums;

although no record of any contribution survives, the published version shows expert

knowledge of timber trees.53 Over the years, millions of trees were planted and

improvements were effected to land and planting procedures.54 Among Fellows of the

senior Society who received medals and became celebrated planters were the fourth Duke

of Bedford (FRS 1742) and Richard Watson, Bishop of Llandaff (FRS 1769).55

Hales’s connection to the Society of Arts may have prompted his suggestion that

Philosophical Transactions should publish ‘Observations on the Growth of Trees’ by the

Norfolk landowner Robert Marsham, containing tables of measurements and cubic content

of oaks and other trees on his estate, collected over specific periods.56 Hales’s comment,

that it might be ‘the means of encouraging the planting of Timber Trees, especially the

Oak, which grows scarce and yet is of the greatest importance to us’ was astute, because

Marsham’s method was widely recommended.57

Introducing, naturalizing and naming foreign trees

During the eighteenth century more than 500 tree species were introduced into Britain,

mainly from North America.58 Miller and Collinson were prominent among Fellows

importing and distributing seeds and young trees, and undertaking trials to propagate and

naturalize them. They sent their American collector shipping instructions,59 and Miller

also addressed the subject in The Naturalist’s and Traveller’s Companion.60 The loss of

valuable seeds in transit or storage also stimulated experiments. John Ellis, for instance,

informed Linnaeus of his many trials to preserve acorns; he also sent some, stored in


Figure 2. Botanical drawing of oak leaves and flower parts by John Miller, Silva (ed. A. Hunter, 1812 edition),vol. 1. (Author’s copy.)



beeswax, to William Aiton, who sowed them successfully at Kew—an experiment that Ellis

presented to the Society, with Aiton’s report.61 Miller described his experiments

demonstrating that seeds ‘need air or they will not grow’.62 During his time at Chelsea,

and until 1799, 50 dried specimens, including exotic trees, were delivered annually to the

Royal Society, where they were displayed and the lists were read at meetings (and

published in Philosophical Transactions).63 Tree specimens included acer, cedar, juniper,

larch, lime, plane, thuya and tulip.64

Among the first to plant exotic trees on a grand scale were the eighth Earl of Pembroke

(FRS 1685) and the second Duke of Richmond (proposed for election in 1724 by Sloane).

Contemporary reports record their passion for collecting trees and their pride in their

plantations; their generosity in sharing seeds, plants and information on culture; and their

encouragement of practical trials.65 Miller hailed Pembroke’s collection at Wilton as ‘the

best in any one Garden in this Kingdom’,66 and ‘the fame and variety’ of Richmond’s


B. Hartley236


Goodwood plantations were recorded in 1754 by Richard Pococke (FRS 1742).67 Such

accounts stimulated visitors and encouraged further planting.

The influx of new species put pressure on botanists to classify and name them. From 1730

Miller strove to standardize nomenclature and correct ‘egregious Mistakes’ causing problems

for gardeners and planters, as well as botanists,68 although he did not adopt Linnaean

binomials until 1768. Although he had earlier acknowledged the benefits of the sexual

system, he thought Linnaeus insufficiently experienced in cultivating plants to distinguish

between species and varieties—because different ‘soils, situations and culture greatly alter

the appearance’.69 Miller is credited with several generic names, including Abies (fir),

Acacia, Castanea (chestnut) and Larix (larch), and with the names of some trees unknown

to Linnaeus.70 In 1807 the Cambridge botanist, Thomas Martyn (FRS 1786) published

The Gardener’s and Botanist’s Dictionary, a revised and enlarged version of Miller’s

work, containing many new tree species. Changes to the classification and nomenclature

of trees, as botanists defined and redefined genera, species and varieties, can be traced

through the various editions of these two works.

Interactions between British and French naturalists

In the 1730s declining forests and shortages of quality timber alarmed the Academie royale

des sciences, as they had the early Royal Society. The agronomist Henri-Louis Duhamel du

Monceau (FRS 1735) and the Comte de Buffon (FRS 1740) were asked to suggest remedies.

Their advice, based on extensive trials and observations (conducted by Duhamel in the royal

forests and by Buffon on his own estates)71 helped to improve planting procedures—in

Britain as well as in France. They were elected to the Royal Society as ‘foreign members’

before this research: Duhamel had undertaken investigations on wood for the Academie,72

and Buffon’s translation of Vegetable Staticks appeared in 1735. Duhamel’s 14 proposers

included Hans Sloane (FRS 1685), Stephen Hales (FRS 1718) and the second Duke of

Richmond (FRS 1724), a renowned planter; Buffon was also endorsed by Sloane, and by

Martin Folkes (FRS 1714). Buffon became known as an authority on trees: he included

some in l’Histoire Naturelle and was cited on several species in the Encyclopedie in the

1750s, but Duhamel was recognized as the era’s foremost forestry expert73—a reputation

fully justified by the extent and rigour of his trials and by the advice he derived from

them, which covered every aspect of raising trees and managing plantations.

Buffon’s most important research followed routes indicated by Evelyn.74 His trials

stripping trees of their bark some time before felling, for instance, were prompted by

Evelyn’s remark that some people advised this; Buffon found—as did his English friend

Nathaniel Hickman (FRS 1725)—that the procedure improved the timber’s strength and

solidity.75 These trials were summarized in the Dublin Literary Journal in 1744 and

1745.76 Duhamel later endorsed Buffon’s conclusions,77 and Miller, noting the

procedure’s success in France, advocated changing the law to allow it in England.78

Alexander Hunter also drew attention to it, quoting Buffon’s explanation for its success:

‘the sappy part . . . becomes as hard as the heart.’79 Duhamel did not cite Sylva directly

but its influence is apparent, especially in Des Semis et Plantations des Arbres et de leur

Culture (1760) and De l’Exploitation des Bois (1764). Duhamel’s works were popular in

England, which he visited in 1750 to compare agricultural practices. Traite de la culture

des Terres (1750–61), based on Jethro Tull’s ideas, appeared as A Practical Treatise of

Husbandry (1759), and the translation of Elements d’Agriculture (1763) announced it was




‘revised by Philip Miller FRS’; both contained sections on trees.80 Such interactions between

British and French naturalists—especially details of their trials—helped to establish good practice.

Buffon’s instructions for planters appeared in two valuable memoirs describing and

evaluating his planting trials: Sur la conservation et le retablissement des forets (1741)

and Sur la culture et l’exploitation des forets (1742).81 These were available at the Royal

Society from 175082 and also appeared, translated and unabridged, in the 1761 edition of

the Earl of Haddington’s influential Treatise on The Manner of Raising Forest Trees.83

Discussing restoring woods in the earlier memoir, Buffon pronounced Evelyn and Miller

knowledgeable and experienced, but because their experiments were on a smaller scale,

he devised his own.84 However, he followed Evelyn in addressing such matters as when

to fell trees and frost protection, and in championing tree nurseries, coppicing, planting

barren land and planting for posterity. He also adopted a comparative approach,

undertaking numerous trials sowing acorns or using young trees, in different soils and

situations, weighing and measuring the produce of particular areas ‘to compare the annual

increase’, and recording failures and successes.85 In 1742 Buffon commended the utility

of his enquiries and observations on methods of protecting sowings of acorns, on ways of

preparing land (no preparation at all produced the best results), and on dealing with

failing trees (cutting them to the ground encouraged new growth because ‘all the strength

of the sap is carried to the roots’ enabling them to ‘shoot out with vigour’).86 Forming

large plantations by using nursery-raised trees he found too costly (which confirmed

Miller’s advice to sow on the spot).

EXPERIMENTAL PHILOSOPHY: INVESTIGATING STRUCTURE, NUTRITION AND GROWTH

Sylva’s genesis within the Society demonstrates the significance to Fellows of the

acquisition and dissemination of knowledge of all aspects of trees and their role in

nature, and explains why many investigated them in addition to encouraging planting. As

Michael Hunter has pointed out, for early Fellows utility was not confined to practical

matters but also meant improving knowledge of nature.87 Trees’ anatomy and growth

were examined from the Society’s earliest years, notably by John Goddard (FRS 1660),

Robert Hooke (FRS 1663) and Nehemiah Grew (FRS 1671). When listing Fellows’

achievements in his history of the Society, Thomas Sprat included the presentation of

observations on ‘the Pores and Valies in wood: the Anatomy of Trees’,88 indicating this

as a subject worthy of enquiry within the Society’s programme of experimental

philosophy. Microscopy and comparative anatomy revealed mysteries of the inner

structure and growth of trees and facilitated insights into the causes of some puzzling

phenomena. Investigations were recorded in Philosophical Transactions and in early

works published by the Society: Hooke’s Micrographia 1665 and three works by Grew—

The Anatomy of Vegetables Begun (1672), to which Hooke contributed microscopic

observations on the pith and pores, The Comparative Anatomy of Trunks (1673) and The

Anatomy of Plants (1682).

Although many Fellows could have seen these works, Evelyn also drew attention to

them in Sylva, with other relevant items: experiments undertaken by the Society in

1663 and 1664 to test the ‘strength and fortitude’ of wood, Merret’s names for tree

parts, Hooke’s microscopical study of petrified wood, and taxonomic information on

tree species taken from Ray’s works.89 In 1664 Evelyn summarized Goddard’s


Figure 3. Comparison of the vessels in a branch of a (left) pine and an oak (right). Tables 32 and 33 in TheComparative Anatomy of Trunks, printed with The Anatomy of Plants (1682 folio edition) (actual size 240 mm �150 mm). (Royal Society Library; copyright q The Royal Society.)

B. Hartley238


anatomical studies of trees.90 Using transverse sections of trunks, Goddard confirmed that,

as was commonly supposed, their size increased by the addition of annual rings that were

larger and more distinct in quicker-growing trees such as fir and ash; a great oak might

have several hundred. He found that rings were broader on the south-facing side and

that firs produced one less ring above each annual row of boughs than below it; that

buds connected through all the rings to the centre, causing knots whose hardness

probably resulted from the fact that their growth was restricted; and that a grafted bud

appeared to root itself into the stock. He investigated the bark (formed of much thinner

rings) and pith, discovering that growth occurred as nourishment reached through ‘all

the Pores and substance’ of the tree, although mostly between bark and body, which

suggested that a tree would die if the bark were cut around. In 1706 Evelyn repeated

this but directed readers to the microscopical studies of trees by Grew, Malpighi (FRS

1669) and Leeuwenhoek.91 The plates in their works were significant in furthering

knowledge of trees by facilitating comparison, which revealed differences between

species in pith, wood and bark, as well as in the sap and air vessels (figure 3). Grew

also considered the effect on the sap of air, which enters, he said, through ‘leaves,

trunk and roots’, insertions in the trunk conveying it from the air vessels into the sap

and back again.92 Goddard seems to have been first to stress the importance of air to

growth, and Hales later found the air in plants ‘very serviceable in carrying on the

work of vegetation . . .’.93




The motion of the sap

The motion of the sap, and especially its apparent ability to defy gravity in ascending to the

tops of trees, exercised many Fellows, stimulating experiment and discussion.94 This was

facilitated by Philosophical Transactions, whose regular appearance encouraged a

reasonably swift exchange of views, demonstrating Oldenburg’s conviction that

communicating ‘the progress of the Studies, Labours, and attempts of the Curious and

learned’ was essential for promoting and improving philosophical matters, advancing

learning and encouraging profitable discoveries.95 A vivid impression emerges of a dynamic

discourse in progress as Fellows responded to each other’s work—on trees as on other matters.

In Micrographia (1665) Hooke investigated the possibility of valves in wood but, despite

diligent endeavours, could not be certain whether the ‘Microscopical pores of Wood or Piths’

contained anything like the ‘Valves in the heart, veins and other passages of Animals . . ..’His experiments to determine the height to which liquid would rise in a small glass

pipe—or ‘artificial pore’—and his speculations on ‘channels or pipes through which the

. . . natural juices of Vegetables are convey’d’,96 were referred to by Boyle when

publishing his own related experiments, conducted in 1668. Boyle thought it possible that

‘Nature, or . . . the most wise Author of it, may have made such Contrivances in Plants, as

to make Liquors ascend in them to the Tops of the tallest Trees’; he considered the

likelihood of something equivalent to valves and discussed the probable effects of heat.97

Christopher Wren (FRS 1660) had also pondered the question of valves, although his

deliberations were not published until 1750. Anatomists agreed, he said, that some pores

present in all wood ‘rise perpendicularly, but with straps’, whereas others run horizontally

from pith to bark. On repeating ‘a known experiment’ to raise water in pipes, he asserted

that ‘Vicissitudes of heat and cold in ye Aire’ were alone sufficient to raise the sap to the

tops of tall Trees, which ‘a Skillfull Engineer’ cannot effect with water ‘without great force

and a Complicated Engine’; but he was certain that valves operated to ‘keep the sap from

falling down’, and that the Sun’s heat caused water drawn in by the root to rise ‘from valve

to valve’ to the top. To demonstrate this, he described an experiment using an apparatus

composed of a glass pipe filled with water, with smaller pipes (part filled) inserted at

intervals, each just below a valve (figure 4); the air in these pipes being heated, the water is

pressed upwards opening the next valve above it; and when the cold contracts the Aire in

the heads . . . the water [in the long pipe] is sucked up to supply it and opens constantly

from valve to valve, let the height be what it will . . . This is what such an Engine will

performe; it remains we should shew that the fabrick of Trees is naturally such a kind

of pneumaticall Engine.

Wren believed this to overturn the idea of ‘a Secret motion in Nature, contrary to that of

Gravity, by which plants aspire upwards’ but added that it ‘may require a great collection

of Phaenomena with a large history of plants to shew how they Expand the leaves and

produce the Seeds and Fruit from the same raine water . . . ’.98 In 1673 Grew discounted

the valve theory, arguing that a branch cut at both ends, ‘ . . . always bleeds . . . upwards

and downwards alike freely . . . ’.99 Later he emphasized the sap’s energy and the pressure

forcing it from the roots up into the pith and bark causing ‘the dilation of the Trunk . . .and the shooting out of the Branches . . . ’ and creating ‘a most ready and copious ascent

of the sap . . . from the bottom to the top of the highest Tree’.100 Hales’s experiments

would eventually confirm ‘the great force of the ascending sap’.101


Figure 4. Apparatus used by Christopher Wren to show how valves might operate in trunks to allow sap to rise fromthe root to the tops of the tallest trees. (Actual size; courtesy RIBA Library Photographs Collection.)

B. Hartley240


Fellows’ interest in these subjects probably inspired the ‘Queries concerning Vegetation,

especially the Motion of the Juyces . . . ’, inserted in Philosophical Transactions in 1668.102

Beale and Dr Ezerel Tonge, a Herefordshire rector, responded quickly; although not a

Fellow, Tonge’s thorough research provoked further trials, as Oldenburg no doubt

expected.103 Beale declared that the juice ascends ‘by the inward Bark’ and ‘after ’tis

concocted to partake of the nature of the plant . . . ’. Tonge found the annual rings ‘full of

Circular Pores’, or ‘Pricks’. To discover whether the sap ascended more in these, or between

the body and the bark, he suggested an experiment, adding that sap taken from a hole bored

into the heart of the tree should indicate differences between the heartwood and the

timber.104 Ray and Francis Willughby (FRS 1663) confirmed Tonge’s ‘prick’t circles’ and

found that sap ascended, not only in these circles and between the body and the bark, but

also ‘through the very Body of the Wood’; it also descended. They discovered that old trees

bled sooner and faster than young ones; that trees bled more if pierced on the north side

than on the south; that a wound made before the sap rises ‘will bleed when it doth rise’; and

that cold weather stopped the flow of sap.105 Their investigations of bleeding in sycamores

appeared in Philosophical Transactions between 1669 and 1671, with some by Martin Lister

(FRS 1671). In 1673 Grew verified the sap’s ascent through wood, bark and pith.106

EIGHTEENTH-CENTURY INVESTIGATIONS OF SAP MOVEMENT: PRACTICAL IMPLICATIONS

The early experimenters focused on improving knowledge of plant structure and the

mechanisms of nutrition and growth without considering practicalities. Even Evelyn, who

quoted William Lawson’s instructions on pruning, did not immediately recognize the

significance of Lawson’s assertion that wasteful boughs and suckers draw sap from the




bole, whereas, if cut close, ‘the strength of all the sap would have gone to the bulk’.107 In

1706, however, Evelyn declared that nothing was ‘more necessary, in order to Pruning,

than the knowledge of the Course and Nature of the Sap’.108

When Bradley, Miller and Hales conducted their investigations into the sap, they

immediately drew attention to the practical implications of their discoveries, with the

clear intention of establishing principles for pruning practices based on solid scientific

evidence. In the preface to Vegetable Staticks Hales wrote:

. . . doubtless a farther insight into the vegetable oeconomy must needs proportionably

improve our skill in Agriculture and Gardening, which gives me reason to hope that

inquiries of this kind will be acceptable to many who are intent upon improving those

. . . Arts: Since they cannot be insensible that the most rational ground for Success in

this laudable pursuit must arise from a greater insight into the nature of Plants.109

Hales’s work is usually analysed in terms of his endorsement of Newtonian ideas—and his

approach to plant physiology was quantitative, with an emphasis on weighing and measuring—

but historians have tended to neglect his significant role in improving tree cultivation.110

Bradley, whose publications preceded Hales’s, had read Grew and recognized that the

cultivation of trees could be improved by a knowledge of their anatomy and physiology.

He showed the role of the sap in growth and why it must be considered when pruning

trees. His first experiments, published in Philosophical Transactions in 1716, included a

microscopical drawing of a branch’s ‘Capillary Vessels’ and an explanation of how its

diameter increases.111 Bradley also clarified the Sun’s role in starting and maintaining the

sap in motion until, in winter, it condenses ‘into the consistency of gum’. He argued

against its all returning to the root in winter (as most people thought)—otherwise, he

asked, ‘How comes it that Trees cut in November and December will put forth Branches

and Leaves the following Spring, though they have no Root or Earth to feed them? This

plainly shews that the Sap is condensed or checked in the Tree’.112 Further experiments

convinced him that the sap vessels must be preserved ‘entire’ and that

At the Time of Transplanting a Tree it was by no means proper to cut off any of the

Branches or wound any of the Vessels, if possible, that the Sap might circulate more

freely and the Tree might remain in better Spirit, till it had renewed its Roots which of

Necessity must be wounded at Transplanting.113

Later Bradley asserted that making great amputations ‘when the Sap is in full Vigour . . . will

weaken and endanger the Tree’.114

Whether Bradley’s research inspired Hales is not known.115 Hales’s plant physiology

considerably advanced understanding of the role of the leaves in promoting growth—of

great consequence to those cultivating trees. He found that the capillary sap vessels in the

trunk imbibe moisture plentifully but require the perspiring leaves to promote its progress,

demonstrating this by showing that a cut branch imbibes water from either end but if the

leaves are removed this ‘soon subsides for want of [their] plentiful perspiration’

(figure 5).116 Although the leaves contain the plant’s ‘main excretory ducts’, designed to

remove redundant fluid, they also draw nourishment up to the young shoots and fruit,

nature taking care to arrange them to ‘render them most serviceable to this purpose’.117

He verified the influence of the Sun’s warmth in expanding the sap in all parts and found

that with its assistance, ‘the force of dilating sap and air’ was sufficient to extend shoots

and expand leaves (figure 6).118


Figure 5. Figures used by Hales in Vegetable Staticks (1727) (opposite p. 88) to demonstrate ‘the great force’ withwhich branches imbibe fluid, and the leaves which draw up the sap and perspire off the surplus. (Actual size; RoyalSociety Library; copyright q The Royal Society.)

B. Hartley242


Because Hales intended his enquiries to improve skills in agriculture and gardening, he

would surely have consulted Miller, England’s foremost gardener, whose tables prepared

from experiments measuring leaf perspiration, featured in Vegetable Staticks, ‘as he

communicated them to me’.119 Hales also described their (separate) experiments with

evergreens, showing that they perspired little and that their ‘thick, viscid, oily sap


Figure 6. Figures 44 and 45 in Vegetable Staticks (1727) (on pages 344 and 350) showing a pierced fig leaf at twostages of growth, used by Hales to demonstrate that ‘the growth and expansion of the leaves is owing to the dilationof the vesicles in every part’. (Actual size; Royal Society Library; copyright q The Royal Society.)



protected them from cold and prevented their leaves from falling’, leading Miller to advise

pruning resinous trees only sparingly.120 In 1730 Hales proposed Miller as a Fellow.

Hales concluded that as trees increase in height, ‘lateral branches shoot out, each lower

order being longer than those immediately above them . . .,’ while if crowded together—as

in woods and groves—the lower branches, perspiring little, die from insufficient

nourishment but the trees grow taller, since the upper branches, exposed to the air,

perspire plentifully, drawing sap to the top.121 Miller and later writers would urge early

thinning of woods to avoid the ill-effects of overcrowding.122 Hales also found that, in

trees growing in the open, ‘the perspiration and attraction’ of the lateral and top branches

were nearly equal, checking upward growth; as the leaves continued to expand, the supply

of sap increased to meet the demand for it.123 He surmised that leaves support vegetable

life as the lungs support animal life, and thought that plants probably drew some

nourishment from the air through their leaves.124 He declared:

The serviceableness of the leaves in drawing up the sap, and the care we see nature takes,

in furnishing the twigs with plenty of them may instruct us . . . not to be too lavish in

pruning them off . . . [and] to be as careful to cut off all superfluous shoots, which we

are assured do draw off in waste great quantities of nourishment . . . .

Comprehending this might offer ‘some useful hints to the Gardiner, in the pruning and

shaping of his trees . . . ’.125


B. Hartley244


Miller quoted Hales at length in Gardener’s Dictionary, applauding him for ‘setting the

Operations of Nature in the Business of Vegetation in a much clearer Light than was ever

before done’ and for clearing up ‘mistaken Notions concerning the Motion of Sap in

plants . . . of great service to promote the more skilful Management of the various Sorts

of Trees’. He urged gardeners to study Vegetable Staticks carefully and to undertake

pruning ‘upon the Principles therein laid down’.126 It is very likely that the utility of

Hales’s discoveries might have been limited without Miller’s making them known to a

wide audience of improving landowners and practical men. Lesley Hanks says that

Buffon applied Hales’s insights on sap movement directly to his forestry research.127

This is apparent in his early investigations with Duhamel on the annual rings and frost

damage to plantations,128 but his memoirs on preserving and cultivating forests, based

on his planting trials, contain nothing on pruning or the role of leaves in promoting

growth. Duhamel, however, cited Hales frequently in all his works, and La Physique

des Arbres (1758), devoted to the anatomy and physiology of trees, contains many of

Hales’s experiments on sap movement, as well as simplified reproductions of his

figures.129

Experiments on air: further benefits of tree planting

In 1659 Beale wrote to Oldenburg, quoting Hartlib:

Trees doe breathe, draw and give breath . . . some plants doth cherish life in some others

and fit ye place for their habitat . . . . ’Tis time for London to think of this and to accept of

a sweete and easy remedy against ye corrosive Smoake and the Sea coale.130

Evelyn addressed this theme in Fumifugium: or the Inconvenience of the Aer and Smoake of

London Dissipated (1661), advising planting sweet-smelling shrubs and trees to combat

London’s ‘infernal Smoake’ and improve the air.131

Scientific support for such views took time to emerge. While Hales found the air ‘full of

acid and sulphureous particles . . . ’ which were ‘imbibed by the leaves . . . ’, he did not

directly infer any improvement to the atmosphere.132 However, Joseph Priestley (FRS

1766)—for whom ‘the discovery of the provision in nature for restoring air . . . injured by

the respiration of animals [was] one of the most important problems in natural

philosophy’—concluded that plants ‘reverse the effects of breathing and tend to keep the

atmosphere sweet and wholesome’.133 Attempting to discover which trees would best

fulfil this purpose, John Ingenhousz (FRS 1769) found those with larger leaves, especially

elm, most effective.134 In 1776 Alexander Hunter’s Silva drew the attention of planters to

Priestley’s remarks.135

Seventeenth-century and eighteenth-century Fellows collected and disseminated

information about trees, encouraged planting and improved their cultivation; their

investigations greatly advanced knowledge of trees’ structure, nutrition and growth.

Professional foresters, who from the 1790s provided instructions for planting and

managing trees, rarely acknowledged their sources but there is no doubt that they

reaped the benefit of the ‘Studies, Labours, and attempts of the Curious and learned’

who preceded them.




APPENDIX 1

The following is the full text of the document presented to the Society on 17 September 1662

by Sir Robert Moray (Royal Society Classified Papers 10 (iii) Agriculture 1660–1740

fol. 20). Michael Hunter kindly assisted me with its transcription.

Quæries touching the Præserving of Tymber now growing And planting more in His

Majesty’s Dominions of England & Wales

1st. Whether it were not adviseable that his most sacred Majesty might be mooved, now

there is so great a scarcity of Tymber for the Supply of his Navie, that all such of his

Forests, Chases & Parks, that ly within 20 Miles of the Sea or any Navigable River,

and whose soyles shall be found fitt for propagating of Tymber for the service of the

Navie, May be planted with Oke, Elme, Ash and Beechen Tymber, in such manner &

proportion as may still consist with His Majesty’s benefitt & pleasure in his Gaine,

And whether the planting of them may be not a farr greater emprovement of those

Lands then is now made.

2. What Proportion of these Forrests Chases and Parks shalbe planted, and whether Hills

or Dales or promiscuously if his most excellent Majesty shall give way thereunto. And

whether that quantity of ground, that shalbe thought fitt to Plant, ought not to be plowed

& sett with Acornes, Ash Keys, Beech Mast, and what the charges of each Acre may

come to per Est[ate] to plant, and from tyme to tyme to fence off. And if any part of

those grounds, shalbe found fitt for planting of Elme—Whether the Transplanting of

young Elmes, be not the most probable way of propagating that sort of Tymber.

3. Whether His Majesty for supply of his Royal Navie, now his owne Tymber in all his

Forests, Chases and Parks being almost wholly cut downe & decayd, might not to have the

refusall of all Oken, Elme, Ash and Beechen Tymber growing upon any Man’s private

Grounds, that is or shalbe offered to sale, before any part of it be butted or sold to any

Private person: [verso] Provided the King give such a valluable consideration & such

security for it as it may be worth, to be agreed for, between the Officers and

Commissioners of His Majesty’s Navy for the tyme being, and the party that owns the

Tymber. And in case they cannot agree in ___ daies after the tymber is felled, & thus

offered to sale, to the Officers and the Commissioners of the Navie, that then the

Owners have Libertie to sell, to whom he please.

4th. Whether it may not be prudence to forbid the building of Houses, in or about the

Citty of London, the Liberties of the same or within 10 Miles of the said Cittie, with

Oken Tymber, unless for Ground Plates, For that the want of Oke may be supplyed with

Firr, which at the distance before mentioned may be bought at reasonable rates. And the

Transport of Firr will not only begett an encrease of seamen, but be also an Advantage

to His Majesty in poynt of Customes.

5th. Whether provision might not be made by Planting Especially of Oaken Tymber,

throughout all his Majesty’s dominions of England & Wales, so as that every owner of

Land may Plow up, Sow or sett with Acornes, One Acre of land, out of each Hundred

Acres. Or so many Oken, or Elm Trees, in Hedgerowes as shalbe equivalent to one

Acre, Sowne or Sett.

ACKNOWLEDGEMENTS

I am grateful to Patrica Fara and Richard Yeo for advice on early and late drafts; to Michael

Hunter for checking my transcription of the document attached as an appendix; and to two

anonymous referees for their helpful suggestions.


B. Hartley246


NOTES

1 John Evelyn, The diary of John Evelyn (ed. E. S. de Beer), 15 October 1662 (Clarendon Press,

Oxford, 1955). Evelyn was proposed as a Fellow in 1660 and was active from that date but was

not formally elected until 1663. On timber shortages see R. G. Albion, Forests and sea power,

chapter 3 (Harvard University Press, Cambridge, MA, 1926) and Lindsay Sharp, ‘Timber,

science, and economic reform in the seventeenth century’, Forestry 48, 51–86 (1975).

2 Thomas Birch, The History of the Royal Society, vol. 1, p. 111 (1761).

3 Pett is identified by his handwriting (see note 5).

4 Entries 18 June, 14 August and 20 June 1662.

5 Letter, Pett to Evelyn, British Library Add. 78317 fol. 23. Evelyn’s Diary (op. cit., note 1)

confirms that he attended Gresham College on 5 November.

6 Evelyn, Sylva 1664, pp. 111–120.

7 Sylva 1670 (see note 15), dedication to the King. Claim supported by John Beale FRS (Anthony

Turner, ‘Natural philosophers, mathematical practitioners and timber in later 17th century

England’, Nuncius 9, 619–631 (1994), at p. 621). See also Stephen Switzer, Iconographia

Rustica, ch. 1 (1718), and Alexander Hunter, dedication in Silva 1776.

8 Evelyn, op. cit. (note 1), 16 and 26 February, 27 October 1664; Birch, op. cit. (note 2), vol. 1,

pp. 212 and 347; Sylva 1664 (imprimatur).

9 Sharp, op. cit. (note 1), assesses other works on timber production, published before and after

Sylva. See also Michael Hunter, Science and society in Restoration England, p. 93

(Cambridge University Press, 1981); William Lynch, Solomon’s child: method in the early

Royal Society of London, ch. 2 (Stanford University Press, 2001); Frances Harris and

Michael Hunter (eds), John Evelyn and his milieu, pp. 17 and 64–65 (British Library,

London, 2003).

10 Birch, op. cit. (note 2), vol. 1, p. 111. (Volume 1 contains all references to Sylva.)

11 Prudence Leith-Ross, ‘The garden of John Evelyn at Deptford’, Garden Hist. 25, 136–152

(1997).

12 Lynch, op. cit. (note 9), pp. 34–35; Thomas Sprat, The History of the Royal Society of London

(1667), p. 85; Birch, op. cit. (note 2), vol. 1, pp. 114–212.

13 See Sprat on Fellows ‘mutually assisting each other’, op. cit. (note 12), p. 76.

14 Evelyn, Sylva 1664, ‘To the Reader’ and see pp. 55, 88–90 and 107–112.

15 Five editions appeared: 1664, 1670, 1679, 1706 and 1729 (the last posthumously).

16 Charles Webster, The Great Instauration, pp. 339–342, 420 and 515 (Duckworth, London,

1975). On Bacon’s heads of inquiry for conducting natural histories see J. Spedding,

R. L. Ellis and D. D. Heath (eds) The Works of Francis Bacon, vol. 1, pp. 389–390

(Longmans, London, 1857).

17 Michael Hunter ‘Robert Boyle and the early Royal Society: a reciprocal exchange in the making

of Baconian Science’, Br. J. Hist. Sci. 40, 1–23 (2007), at p. 19.

18 Phil. Trans. 1, 91–96 (1665). The committee was founded in 1664 at John Beale’s suggestion

(Birch, op. cit. (note 2), vol. 1, pp. 402 and 407).

19 Phil. Trans. 1, 186–189 (1665–66).

20 Part-published by Hartlib in 1652 (Webster, op. cit. (note 16), p. 431).

21 Robert Plot, Enquiries propounded to the most Ingenious of each County in my travels through

England and Wales (Bodleian Ash 1820), fos 222–225, trees on p. 222. Forests and woods are

marked on Plot’s maps. See also William Marshall’s County Surveys from 1787; Thomas

Martyn, The Gardener’s and Botanist’s Dictionary, vol. 1 (Woods) (1807).

22 Plot describes such trees in chapter 6 in both works: John Ray, Catalogus Plantarum and

Historia Plantarum.

23 Evelyn, Sylva 1664, p. 124.

24 The timber content of great trees—fallen or felled—was regularly recorded.




25 Evelyn, Sylva 1664, ‘To the Reader’; Birch, op. cit. (note 2), vol. 1, pp. 10–11. Bacon’s topics

for such a History included agriculture and gardening (Spedding et al., op. cit. (note 16), vol. 1,

pp. 405–411). On Evelyn’s contributions see W. E. Houghton, ‘The history of trades’, J. Hist.

Ideas 2, 33–60 (1941), at pp. 47–56.

26 Hunter, op. cit. (note 9), p. 26.

27 Webster, op. cit. (note 16), pp. 99, 502 and 514–516; Sharp, op. cit. (note 1), pp. 34 and 61.

28 Webster, op. cit. (note 16), pp. 469–471; Hunter, op. cit. (note 9), p. 37.

29 See Mayling Stubbs, ‘John Beale, philosophical gardener of Herefordshire, part 1’, Ann. Sci. 39,

463–489 (1982), at pp. 485–488; idem, ‘John Beale, philosophical gardener of Herefordshire,

part 2’, Ann. Sci. 46, 323–363 (1989).

30 Evelyn, Sylva 1664, pp. 105–107.

31 William Lawson, A New Orchard and Garden (1631), quoted by Evelyn, Sylva 1664, pp. 74–78

(and subsequent editions).

32 Leith-Ross, op. cit. (note 11), p. 147; John Evelyn, Directions for the Gardiner at Says-Court

c. 1687 (ed. G. Keynes), pp. 39–42, 60–61 and 68 (Nonsuch Press, London, 1932).

33 Evelyn, Sylva 1664, pp. 10–11 and 105.

34 Sylva (1706), pp. 361–374. Switzer, op. cit. (note 7), pp. 248–255, and Richard Bradley’s

1727–28 edition of Houghton’s A Collection for the Improvement of Husbandry and Trade

(1692–1703), vol. 3, p. 180 (see notes 35 and 39). Evelyn’s Terra, a Philosophical Discourse

of Earth, published by the Society in 1675, was printed with Sylva from 1679.

35 John Houghton, op. cit. (note 34), 15 no. 409; 16 no. 483.

36 Evelyn, Sylva 1664, p. 107; advertisement, Phil. Trans. 2, 398 (1666) [no author].

37 Moses Cook, The Manner of Raising, Ordering and Improving Forest Trees, pp. 1–2

(1679).

38 Appointed in 1724. See H. H. Thomas, ‘Richard Bradley, an Early Eighteenth-Century

Biologist’, Bull. Br. Soc. Hist. Sci. 1949–54, 176–178; Blanche Henrey, British Botanical

and Horticultural Literature before 1800, vol. 2, pp. 435–454 (Oxford University Press, 1975).

39 Bradley, revised edition of Houghton’s Collection (note 34), vol. 3; and Plot’s Enquiries

(note 21), vol. 4, pp. 292–298.

40 Foreign admirers included l’abbe le Blanc (Lettres d’un Francois, vol. 2, p. 94 (1745)) and the

Swedish naturalist Pehr Kalm (Henrey, op. cit. (note 38), vol. 2, pp. 217–218). See also Richard

Pulteney FRS, Historical and Biographical Sketches of the Progress of Botany in England, vol.

2, p. 245 (1790).

41 Philip Miller, Gardener’s Dictionary 1759 (Quercus; Planting).

42 Miller, Gardener’s Dictionary 1731, 1768 (Preface); 1759 (title page).

43 Miller, Gardener’s Dictionary 1759 op. cit. (Pinus, Planting, Lopping).

44 Martyn, (note 21), pp. ix–x; H. le Rougetel, The Chelsea gardener, pp. 57–60 (Natural History

Museum, London, 1990).

45 John Claudius Loudon, Encyclopaedia of Gardening, p. 1139 (1822).

46 Evelyn adopted the spelling Silva in 1706.

47 Alexander Hunter, Silva (Preface). Martyn recorded that Banks’s woods had been ‘very carefully

managed since 1727’ op. cit. (note 21) I (Woods).

48 Banks–Hunter letters (Kew, BA 1, fos 47 and 55–56). Hunter later thanked Banks for ‘favours’

(Silva 1812, p. viii). By engraving the plates himself, the artist, John Miller, also ensured their

accuracy.

49 Welbeck Abbey, Portland archive. Silva 1776, pp. 90–100.

50 Hunter, op. cit. (note 9), pp. 110–111. See also Neil Chambers, ‘The Society of Arts and Joseph

Banks: a first step in London learned society’, Notes Rec. R. Soc. 61, 313–325 (2007).

51 Edward Wade, A Proposal for Improving and Adorning the Island of Great Britain, presented on

26 March 1755; published in 1755. Wade also cited Hales on sap movement and pruning.

52 Minutes of the Society of Arts 1754–57, vol. I, 18 April 1756.


B. Hartley248


53 Ibid., vol. 2, pp. 13–14 (16 March 1757) and p. 27 (30 March 1757). Collinson refused (Linnean

Society, Collinson correspondence, letter 23 March 1757); Ellis had joined in 1755 and Miller’s

occasional attendance in an advisory capacity is recorded.

54 Society of Arts Transactions, vol. 1, pp. 73 and 79–80 (1783); H. T. Wood, A history of the Royal

Society of Arts, p. 150 (John Murray, London, 1913).

55 Ibid. pp. 145–147.

56 Phil. Trans. 51, 7–12 (1759).

57 Hales to Ellis, 18 December 1758 (British Museum, Birch papers Add. 4309, fo. 45). Marsham

quoted by Nathaniel Kent, Hints to Gentlemen of Landed Property, p. 203 (1775) and Martyn,

op. cit. (note 21), vol. 1 (Woods).

58 J. C. Loudon, Arboretum et Fruticetum Britannicum, vol. 1, p. 84 (1835–38).

59 Alan Armstrong, ‘Forget not Mee & My Garden . . . ’: Selected Letters, 1725–1768, of Peter

Collinson, F.R.S., p. 25 (American Philosophical Society, Philadelphia, PA, 2002).

60 Philip Miller, The Naturalist’s and Traveller’s Companion, p. 20 (1772).

61 John Ellis, Linnean Society, Notebooks 1758–59, vol. 1, p. 1, and vol. 2, pp. 30–31; Phil. Trans.

58, 75–79 (1768).

62 Philip Miller, Gardener’s Dictionary 1768 (Planting).

63 According to the terms of Sloane’s deed establishing the Physic Garden in 1722. See Ruth

Stungo, ‘The Royal Society specimens from the Chelsea Physic Garden 1722–1799’, Notes

Rec. R. Soc. 47, 213–224 (1993), especially pp. 214–215.

64 Ruth Stungo, ‘Trees in the Chelsea Physic Garden in the eighteenth century’, International

Dendrology Society Yearbook 1991, pp. 72–76.

65 See, for instance, Miller’s preface to Catalogus Plantarum, pp. vii–ix (Society of Gardeners,

1730); Miller is identified as the author by Pulteney, op. cit. (note 40), vol. 2, p. 244.

66 Miller, op. cit. (note 65), p. vii.

67 Richard Pococke, Tours 1754–1756, p. 111 (1888).

68 Miller, op. cit. (note 65), p. ix.

69 Philip Miller, A Short Introduction to the Science of Botany, pp. 5–11 (1760).

70 W. T. Stearn, ‘The Botanical Importance of Philip Miller’s Publications’, in le Rougetel, op. cit.

(note 44), pp. 170–180.

71 See Lesley Hanks, Buffon avant l’‘Histoire Naturelle’ (Presses Universitaires de France, Paris,

1966), especially chapter 2.

72 Ibid., p. 146.

73 Ibid., pp. 189–190 (Buffon) and 140–149 (Duhamel du Monceau).

74 Ibid., p. 167.

75 Buffon, ‘Moyen facile d’augmenter la solidite, la force at la duree du bois’ (1740) (cited by

Hanks, op. cit. (note 71), p. 167); Evelyn, Sylva 1664, p. 93. Plot also described this practice

(Natural History of Oxfordshire (1677), p. 166; Natural History of Staffordshire (1686),

p. 384; and ‘A Discourse concerning the most seasonable Time of Felling of Timber’, Phil.

Trans. 16, pp. 455–461 (1686–92)). For more on Plot see Turner, op. cit. (note 7), pp. 628–630.

76 Anon., ‘How to make Timber for Service strong and durable’, Literary J. (Dublin) 1, 13–16 (1744);

‘Mr. Buffon’s Account of Experiments in Planting Trees’, ibid. 1, 356–360 (1745); ‘Observations

and Experiments on the Strength of Timber by Mr. Buffon’, ibid. 2, 141–148; 3, 121–132 (1745).

77 Duhamel du Monceau, De l’Exploitation des Bois, p. 412 (1764).

78 Philip Miller, Gardener’s Dictionary, Preface (1752); Quercus (1759).

79 Alexander Hunter, Silva 1776, p. 512.

80 Duhamel du Monceau, Elements of Agriculture (1764) (title page).

81 Histoire de l’Academie Royale des Sciences (1741), pp. 140–156; (1742), pp. 233–246.

82 In 1750 the Academie sent its Memoires to the Society (via Buffon), in exchange receiving

Philosophical Transactions (Hanks, op. cit. (note 71), p. 266 and note 46); abstracts of

Buffon’s memoirs also appeared in Journal des Scavans in December 1743 and March 1746.




83 Buffon, ‘On Preserving and Repairing Forests’ and ‘On the Culture of Forests’, in Earl of

Haddington’s Treatise on The Manner of Raising Forest Trees, pp. 80–105 and 108–129

(written in ca. 1732–35 but first published in 1756).

84 Buffon in Haddington, ibid., pp. 92–94. For Buffon on stripping trees see p. 91.

85 Ibid. pp. 80–105.

86 Duhamel disagreed with this practice (Des Semis et Plantations des Arbres et de leur Culture

(1760), p. lvii).


88 Sprat, op. cit. (note 12), p. 242.

89 Sylva: 1670 pp. 182–184; 1679 pp. 173–175; 1706 pp. 233–239, 282, 259–261.

90 Sylva 1664, pp. 88–90.

91 Sylva 1706, p. 236.

92 Nehemiah Grew, The Comparative Anatomy of Trunks, pp. 48–69 (1673).

93 Stephen Hales, Vegetable Staticks, pp. 319–320 (1727).

94 After Harvey’s discoveries it was common to liken sap vessels to arteries and veins, and several

Fellows, including Hooke, Beale, Bradley, Grew and Hales, discussed circulation.

95 Phil. Trans. 1, 1–2 (1664/5).

96 Robert Hooke, Micrographia, vol. 1, pp. 10–11, 116 and 114 (1665).

97 M. Hunter and E. B. Davis (eds), The Works of Robert Boyle, vol. 6, pp. 106–108 (Pickering &

Chatto, London, 1999). See also review of Boyle’s ‘New Experiments’, Phil. Trans. 3, 845–

850 (1668).

98 This undated experiment, although recorded in another hand, is presumed to have been by

Wren. It is tipped in between pp. 242–243 of the Royal Institute of British Architects’

‘Heirloom’ copy of Wren’s son’s Parentalia: Memoirs of the Family of the Wrens (1750);

‘Of the rising of the Sap in Trees’ is item XXXVI on a list of Wren’s manuscript and

printed tracts (p. 243). I am grateful to Jim Bennett for informing me of this experiment.

99 Grew, op. cit. (note 92), pp. 125–126.

100 Grew, The Anatomy of Plants, pp. 71–78 (1682).

101 Hales, op. cit. (note 93), p. 359.

102 ‘Queries concerning Vegetation, especially the Motion of the Juyces . . .’, Phil. Trans. 3,

797–801 (1668).

103 On the benefits of communicating with provincial Fellows and others see M. B. Hall, ‘The

Royal Society’s role in the diffusion of information in the seventeenth century’, Notes

Rec. R. Soc. 29, 173–192 (1975).

104 John Beale and Ezerel Tonge on sap movement, Phil. Trans. 4, 853–862; 877–881; 913–923

(1668/9).

105 John Ray and Francis Willughby on sap movement, Phil. Trans. 4, 963–965 (1668/9).

106 Grew, op. cit. (note 92), pp. 41–43.

107 William Lawson, quoted Evelyn, Sylva 1664, pp. 73–76.

108 Sylva 1706, pp. 206–207.

109 Hales, op. cit. (note 93), pp. iii–iv.

110 For instance, D. G. C. Allan and R. E. Schofield, who discuss Hales’s work in depth, ignore his

remarks on pruning and only mention in passing that he recommended his conclusions to

gardeners and farmers (Stephen Hales, Scientist and Philanthropist, p. 47 (Scholar Press,

London, 1980)).

111 Richard Bradley, ‘Observations and Experiments relating to the Motion of the Sap in

Vegetables’, Phil. Trans. 29, 486–490 (1716).

112 Richard Bradley, New Improvements of Planting and Gardening, pp. 1–8 (1717).

113 Richard Bradley, Monthly Register of Experiments and Observations (May 1722), p. 68.

114 Richard Bradley, General Treatise (1726 edition), vol. 1, p. 286.

115 See Allan and Schofield, op. cit. (note 110), p. 31.


B. Hartley250


116 Hales, op. cit. (note 93), Experiments 13–15 and 28, pp. 45–47 and 90.

117 Ibid., pp. 324 and 370.

118 Ibid., Experiments 124 and 20, pp. 344–346.

119 Ibid., pp. 22–27; Experiments 3–5, pp. 18–22, 49 and 69.

120 Ibid., Experiment 5 (and Miller’s), pp. 20–22 and 321. Gardener’s Dictionary 1759 (Lopping).

121 Hales, op. cit. (note 93), Experiment 124, pp. 348–353.

122 Gardener’s Dictionary 1768 (Woods).

123 Hales, op. cit. (note 93), pp. 354–355.

124 Ibid., pp. 319 and 323–326.

125 Ibid., pp. 370–374.

126 Gardener’s Dictionary 1759/1768 (Sap).

127 Hanks, op. cit. (note 71), pp. 90, 158 and 169–174.

128 Buffon and Duhamel du Monceau, Recherches de la cause de l’excentricite des couches

ligneuses . . . and Observations des differens effects que produisent sur les vegetaux les

grandes gelees d’hiver et les petites gelees du printemps, published by the Academie in 1740.

129 Duhamel du Monceau, La Physique des Arbres, pp. 134–182 and 230–249 (1758) (figures

from Vegetable Staticks on Plate 4). Duhamel also drew on Grew, Malpighi and Charles

Bonnet (FRS 1743).

130 A. Hall & M. R. Hall (eds) The Correspondence of Henry Oldenburg, vol. 1, pp. 318–319

(University of Wisconsin Press, Madison, WI, 1965).

131 National Smoke Abatement Society reprint (1933), pp. 11 and 37–39. The plantations of limes

in St James’s Park probably resulted from Evelyn’s remarks on their wholesome properties

(Loudon, op. cit. (note 58), vol. 1, p. 368).

132 Hales, op. cit. (note 93), pp. 256–257 and 324.

133 Joseph Priestley, ‘Observations on Different Kinds of Air’, Phil. Trans. 62, 147–264 (1772).

134 John Ingenhousz, Experiments upon Vegetables, pp. xv–xxxv (1779).



history faculty, university of oxford, old boys’ high...

Documents